Construction of Zeolite/Fe2ZnTiO6/graphene oxide multifunctional nanocomposite with high efficiency for photocatalytic removal of inorganic pollutants under visible irradiation

Abstract

Nowadays, pollutants of toxic heavy metals (THMs), nitrate (NO3-), and carbon dioxide (CO2) are three types of important environmental pollutants that have become a global concern. In recent years, perovskite photocatalysts have created great development prospects in pollutants treatment of aqueous solutions, industrial wastewaters, and air. Herein, Zeolite/Fe2ZnTiO6 (FZTO) double perovskite/graphene oxide (GO) nanocomposite (NC) was prepared as a highly efficient multifunctional perovskite photocatalyst by the sol-gel method. The crystal structure, morphology, and composition of the synthesized nanocomposite were characterized by XRD, SEM, and EDX-Map analysis. Also, photocatalytic mechanisms of the Zeolite/Fe2ZnTiO6/graphene oxide nanocomposite were evaluated by PL, DRS, and UV–visible analysis. Photocatalytic activity of Zeolite/Fe2ZnTiO6/graphene oxide nanocomposite was evaluated for the removal of toxic heavy metals, nitrate, and carbon dioxide pollutants in experiment conditions including pH (1–9), the temperature (25–65 °C), stirring speed (100–500 rpm), retention time (1–6 h), photocatalyst dosage (0.25–1.5 g/l), pollutants concentration (5–120 mg L−1) and distance between the visible source and solution surface (5–20 cm). The UV–visible spectrums were shown the removal efficiency of 90% for toxic heavy metals in optimal conditions of pH;7, temperature; 25 °C, stirring speed; 200 rpm, retention time; 5h, photocatalyst dosage; 1 g/l, THMs concentration; 10 mg L−1, and distance between the light source and solution surface; 10 cm under visible light irradiation. Also, the highest degradation efficiency of NO3− pollutant from aqueous solution was determined at about 85% in optimized conditions of pH; 3, temperature; 25 °C, agitation rate; 200 rpm, reaction time; 5h, photocatalyst dosage; 1 g/l, NO3−concentration; 100 mg L−1, and distance between the surface of the solution and light source; 10 cm under visible light irradiation. Finally, conversion maximum of CO2 pollutant was obtained at about 80% in optimum conditions of pH; 3, temperature; 25 °C, mixing rate; 200 rpm, retention time; 5h, photocatalyst dosage; 1 g/l, CO2 concentration; 100 mg L−1, and distance between the solution surface and light source; 10 cm under visible light irradiation.